Got my hands on a unit. I've always loved these things.....spent one night with a bottle of whisky getting this one all set up: http://www.youtube.com/watch?v=vz25nWP0Cus Sorry about the bad video quality.....it was a spur of the moment kind of thing.
Pretty cool; set up. Just a shame Palcom went on to make pretty much piss poor Mega Drive games. Mega Drive Double Dragon 2, anyone?
I have the european version of the PX-7, its actually quite good just as an MSX because of the quality keyboard. The video input features are quite amusing for a while too, have played with some basic over visualisations.